This invention relates to servicing of remote medical diagnostic systems from a central service facility via a network and, more particularly, to remote servicing of ultrasound imaging systems via a network.
A conventional ultrasound image is composed of multiple image scan lines. A single scan line (or small localized group of scan lines) is acquired by transmitting focused ultrasound energy at a point in the region of interest, and then receiving the reflected energy over time. The focused transmit energy is referred to as a transmit beam. During the time after transmit, one or more receive beamformers coherently sum the energy received by each channel, with dynamically changing phase rotation or delays, to produce peak sensitivity along the desired scan lines at ranges proportional to the elapsed time. The resulting focused sensitivity pattern is referred to as a receive beam. Resolution of a scan line is dependent on the directivity of the associated transmit and receive beam pair.
In a typical ultrasound imaging system, the output signals of the beamformer channels are coherently summed to form a respective pixel intensity value for each sample volume in the object region or volume of interest. These pixel intensity values are log-compressed, scan-converted and then displayed as an image of the anatomy being scanned.
Conventional ultrasound beamformers use dynamic focusing during reception of echoes. With this method, the
Conventional ultrasound beamformers use dynamic focusing during reception of echoes. With this method, the beamformation process is optimized for each depth to achieve as good a beamshape as possible (i.e., narrow beamwidth with low sidelobes). In most systems, a single fixed focus is used during transmit beamformation in attempting to maintain a good combined beamshape. In areas away from the transmit beam focus, the beamwidth of the resultant beam widens and the sidelobes increase.
In the manufacture of an ultrasound system, beamformer control is installed in either algorithmic or tabulated form, and is optimized with the assumption that all system channels are functional. If any of the system channels become defective, image quality is degraded due to increased sidelobes in the ultrasound beam. If the degradation is severe enough, or if the customer is sensitive enough to detect the loss in image quality, a service call of high priority is triggered and a field engineer has to travel to the customer site immediately to repair the defective system. Alternatively, the system might detect the defective channels during self-diagnosis and possibly send that information to the service organization through a remote link. Again, in this instance, a field engineer must repair the defective hardware (preferably before the customer detects the defect.) In either instance, the beamformer controller does not utilize the information relating to defective channels in order to minimize their impact on image quality.
Ultrasound imaging systems of the type described above are often called upon to produce reliable and understandable images within demanding schedules and over a considerable useful life. To ensure proper operation, the systems are serviced regularly by highly trained personnel who address imaging problems, configure and calibrate the systems, and perform periodic system checks and software updates. Moreover, service offerings have been supplemented in recent years by service centers capable of contacting scanners at subscribing institutions directly, without need for intervention on the part of the institution personnel. Such centralized servicing is intended to maintain the ultrasound imaging systems in good operational order without necessitating the attention of physicians or radiologists, and is often quite transparent to the institution.
In certain centralized servicing systems, a computerized service center may contact a scanner via a network to check system configurations and operational states, to collect data for report generation, and to perform other useful service functions. Such contacts can be made periodically, such as during system xe2x80x9csweepsxe2x80x9d,in which a variety of system performance data are collected and stored with historical data for the particular scanner. The data can then be used to evaluate system performance, propose or schedule visits by service personnel, and the like.
Currently available service systems also permit some degree of interaction between service centers and institutions. For example, a known interactive service system facilitates valuable exchanges of information, including reports of system performance, feedback on particular incidents requiring attention, updates of system licenses, software, and imaging protocols, etc. In particular, a platform has been developed that allows a central service facility to exchange information on possible service problems with remotely located scanners, and to retrieve information or data log files from scanners for the purpose of servicing those scanners.
An integrated user-interactive platform for servicing diagnostic equipment at remote locations may be configured in software, hardware, or firmware at the scanner, or may be installed in a central operator""s station linking several scanners in a medical facility. The user interface permits service requests to be generated prior to, during, or subsequent to, examinations executed on the diagnostic equipment. The user interface also permits service messaging, report generation and retrieval, etc. The user interface is preferably configured as a network browser, which also facilitates linking the scanner or the central facility control station to a network such as an intranet or the Internet.
The existence of a networked system for allowing centralized servicing of remote scanners makes it possible to modify the beamformer control function in a remote ultrasound imaging system from a central location to compensate for defective beamformer channels.
A system for servicing a remotely located ultrasound beamformer from a central service facility via a network allows a service organization to repair an ultrasound beamformer in a remotely located ultrasound imaging system. Assuming that one or more beamformer channels are defective, the system will provide degraded images. While the system might detect the defective channels, the pre-installed beamformer control software has been optimized assuming all channels to be functional.
The servicing method, in accordance with a preferred embodiment of the invention, produces beamformer control software (i.e., beamforming parameters) that is optimized for the existing functional channels. The beamformer control software is generated at the central service facility based on diagnostic feedback received from the remotely located system via a network. This new beamformer control software is then downloaded to the remote system via the same network. Subsequent operation of the ultrasound imaging system is in accordance with the new beamforming parameters. Although the resulting beam characteristics are not as good as those for a fully functional system, the resulting beam characteristics are drastically improved over those produced by the uncompensated defective system. Therefore, the image quality of the repaired remote system can be almost as good as the quality of a non-defective system.
The method of operation in accordance with a preferred embodiment is implemented as follows. The system controller of each ultrasound imaging system is programmed to perform a diagnostic routine during startup and to transmit the diagnosis results to the central service facility via a network (e.g., the Internet). The diagnosis results are analyzed at the central service facility. A beamformer control server identifies defective channels and generates optimized beamformer control software to compensate for them. In particular, the optimized beamformer control software is designed to reduce sidelobes in the beam profile which would be produced by the beamformer with defective channels. In accordance with the preferred embodiment, the beam profile, i.e., the aperture function, is numerically optimized. The optimized beamformer control software is then downloaded to the remote system with defective beamformer channels via the network.
Eventually, the remote system will require hardware servicing to replace the defective beamformer channels. In the interim however, the impact of the defective channels can be minimized by the transmission via a network of optimized beamformer control software which mitigates the image degradation due to those defects. The result is reduced urgency for the hardware service.
A preferred embodiment of the servicing system comprises a central service facility coupled to a multiplicity of remotely located beamformers via a network. Each beamformer comprises: means for diagnosing the beamformer to determine the state of the beamformer channels; means for transmitting the diagnosis results to the network addressed to the service facility; means for receiving optimized beamformer control software from the network; and means for installing the optimized beamformer control software in the beamformer. The service facility comprises: means for receiving the diagnosis results via the network; means for generating optimized beamformer control software if the diagnosis results indicate presence of one or more defective beamformer channels; and means for transmitting the optimized beamformer control software to the network addressed to the beamformer. The optimized beamformer control software, whether in algorithmic or tabulated form, is formulated to reduce sidelobes in the beam profile produced by the beamformer with defective beamformer channels.
In an alternative preferred embodiment, the system controller of the remote ultrasound imaging system can be programmed to generate its own optimized beamformer control software. There are, however, limitations on available processing power and the ability to check the results.